Nature has evolved materials that possess mechanical properties surpassing many man-made composites. Bones, teeth, spider silk, or nacre, are just a few well-known examples of biomaterials that exhibit exceptionally high tensile strengths, hardness, or toughness. [1][2][3][4][5][6] These remarkable properties have driven scientists to study and model their architectures and compositions, from micro-to nanoscales, in the hope of developing analogous synthetic materials. Of these, probably the most studied is nacre. [4,[7][8][9][10][11][12][13][14][15] It is composed of 95 % brittle CaCO 3 plates with just a few percent of organic "glue", yet it is twice as hard and more than ca. 1000 times as tough as its constituent phases. [16] These exceptional mechanical properties together with the macroscopic beauty and elegance of its nanoscale hierarchy serve as a model for design of high-performance materials. Preparation of artificial analogs of nacre has been approached by using several different methods and the resulting materials capture some of the characteristics of the natural composite. [17][18][19][20][21][22][23] In our own work, we have used a layerby-layer (LBL) assembly technique to prepare a nanostructured analogue of nacre from inorganic nanometer-sized sheets of Na + -Montmorillonite clay (C) and a polyelectrolyte, poly(diallyldimethylammonium chloride) (PDDA).[24] The structure, deformation mechanism, and mechanical properties of this material were found to be comparable with those of natural nacre and lamellar bones (tensile strength, r = (100 ± 10) MPa, and Young's modulus, Y = (11 ± 2) GPa). Contrary to other preparation techniques the LBL method is relatively simple and highly versatile in merging different functionalities into a single composite. [25][26][27] At the same time, a vast array of available assembly components allows us to generate alternative designs as a means of understanding the different interactions necessary for preparation of nacrelike composites with application-tailored mechanical responses. LBL technique has proven to be an ideal method for preparation of multifunctional, nanostructured materials. Since its inception in 1990s, [28] there has been a virtual explosion in the amount of scientific literature in this subject. Similarly, LBL assembly of clays was also pioneered and further studied in the 1990s by Ferguson's group. [29,30] Since then, the LBL technique has been found to be applicable for the preparation of superhydrophobic surfaces, [31] sensors and semipermeable membranes, [32][33][34][35] drug and biomolecules delivery, [36,37] optically active and responsive films, [38][39][40] fuel cells and photovoltaic materials, [41,42] biomimetic and bioresponsive coatings, [43] semiconductors, [44,45] catalysts, [46] and magnetic devices, [26,47] to name a few. All of the potential applications mentioned above also require both control and improvement of mechanical properties. Using the mix-and-match approach to LBL films, that is, stratified multilayers, [25,26,44] the mecha...